On a miserable wet day, a Grey Heron had taken advantage of the absence of the Coots and had taken over their patriotically decorated nest. It looks soggy and hunched up, but under its wet outer feathers is a thick layer of bone-dry inner feathers, and it is warm enough.

Ducks don't get wet at all, of course -- the raindrops just roll off them in the proverbial manner. Here are two of a group of six Red Crested Pochards which had found some interesting waterweed near the bridge and were diving to bring it up and eat it.

They are still in eclipse, and at this time the sexes have similar plumage, but you can tell the male by his red bill.  There is a permanent population of Red Crested Pochards in Central London, descended from escapes from waterfowl collections in the parks, but now established as a breeding species and gradually growing in number.

Mandarins also arrived in the same way, and have similarly become feral and started increasing their numbers. Three of this year's brood were on the edge of the Serpentine.

I am not sure that all four have survived, but I often see a solitary young Mandarin and this may be the fourth one, which has struck out on its own.

The eldest pair of Great Crested Grebe chicks were out on the Serpentine, playing together with sticks and bits of weed brought up from the bottom. They can now stay down for quite a long time when they dive.

They abandoned their game when their mother came with a good-sized fish.

The one that didn't get the fish looks very disappointed when its mother resurfaces empty-beaked. But actually both of them are very well fed, and their parents carefully prevent the stronger chick from grabbing all the food, dodging around it as they approach the other chick, and if necessary chasing it away.

One or more of the Hobbies was being mobbed by Ring-Necked Parakeets this morning, in a tree near the Round Pond, but it or they had gone deep into the leaves and couldn't be seen.